nope you guys are totally wrong, ofp does support armour,head,legs and arms diffeent armour points.
The NAM pack for example as different values defined for each soldiers, for example in the Delta I'm making with BAS they have a simulation of vest, making them hold 2 more shots in the vest. Instead of 2 they take 4 in the vest and the head,legs and shoulders still have the normal soldier hit values.
For that there are some lines you have to use in the cpp file wich defines the structure of the soldier and than the different armour values.
Chech the NAM Pack's cpp file and see what I mean, they will be engaged as normal soldiers, but they have some advantage due to wearing a good vest or helmet.
However try to make it real not imposible, don't think of them as super units just as more than regular quality ;D